[PATCH] x86: fux duplicated X86_BUG(9) macro

[PATCH] x86: fux duplicated X86_BUG(9) macro

[Dave Hansen]

Now sending with actual stable@ address...

--

From: Dave Hansen <dave.hansen@linux.intel.com>

cpufeatures.h currently defines X86_BUG(9) twice on 32-bit:

	#define X86_BUG_NULL_SEG        X86_BUG(9) /* Nulling a selector preserves the base */
	...
	#ifdef CONFIG_X86_32
	#define X86_BUG_ESPFIX          X86_BUG(9) /* "" IRET to 16-bit SS corrupts ESP/RSP high bits */
	#endif

I think what happened was that this added the X86_BUG_ESPFIX, but
in an #ifdef below most of the bugs:

	[58a5aac5] x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled

Then this came along and added X86_BUG_NULL_SEG, but collided
with the earlier one that did the bug below the main block
defining all the X86_BUG()s.

	[7a5d6704] x86/cpu: Probe the behavior of nulling out a segment at boot time

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: stable@vger.kernel.org
---

 b/arch/x86/include/asm/cpufeatures.h |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff -puN arch/x86/include/asm/cpufeatures.h~fix-x86-bugs-macros arch/x86/include/asm/cpufeatures.h
--- a/arch/x86/include/asm/cpufeatures.h~fix-x86-bugs-macros	2016-06-17 17:10:30.978602807 -0700
+++ b/arch/x86/include/asm/cpufeatures.h	2016-06-17 17:10:30.982602989 -0700
@@ -301,10 +301,6 @@
 #define X86_BUG_FXSAVE_LEAK	X86_BUG(6) /* FXSAVE leaks FOP/FIP/FOP */
 #define X86_BUG_CLFLUSH_MONITOR	X86_BUG(7) /* AAI65, CLFLUSH required before MONITOR */
 #define X86_BUG_SYSRET_SS_ATTRS	X86_BUG(8) /* SYSRET doesn't fix up SS attrs */
-#define X86_BUG_NULL_SEG	X86_BUG(9) /* Nulling a selector preserves the base */
-#define X86_BUG_SWAPGS_FENCE	X86_BUG(10) /* SWAPGS without input dep on GS */
-
-
 #ifdef CONFIG_X86_32
 /*
  * 64-bit kernels don't use X86_BUG_ESPFIX.  Make the define conditional
@@ -312,5 +308,7 @@
  */
 #define X86_BUG_ESPFIX		X86_BUG(9) /* "" IRET to 16-bit SS corrupts ESP/RSP high bits */
 #endif
+#define X86_BUG_NULL_SEG	X86_BUG(10) /* Nulling a selector preserves the base */
+#define X86_BUG_SWAPGS_FENCE	X86_BUG(11) /* SWAPGS without input dep on GS */
 
 #endif /* _ASM_X86_CPUFEATURES_H */
_

Re: [PATCH] x86: fux duplicated X86_BUG(9) macro

[Andy Lutomirski]

On Fri, Jun 17, 2016 at 5:15 PM, Dave Hansen <dave@sr71.net> wrote:
>
> Now sending with actual stable@ address...
>
> --
>
> From: Dave Hansen <dave.hansen@linux.intel.com>
>
> cpufeatures.h currently defines X86_BUG(9) twice on 32-bit:

Acked-by: Andy Lutomirski <luto@kernel.org> # who is suitably embarrassed

That being said, you or Ingo should consider fixing the typo in $SUBJECT.

>
>         #define X86_BUG_NULL_SEG        X86_BUG(9) /* Nulling a selector preserves the base */
>         ...
>         #ifdef CONFIG_X86_32
>         #define X86_BUG_ESPFIX          X86_BUG(9) /* "" IRET to 16-bit SS corrupts ESP/RSP high bits */
>         #endif
>
> I think what happened was that this added the X86_BUG_ESPFIX, but
> in an #ifdef below most of the bugs:
>
>         [58a5aac5] x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled
>
> Then this came along and added X86_BUG_NULL_SEG, but collided
> with the earlier one that did the bug below the main block
> defining all the X86_BUG()s.
>
>         [7a5d6704] x86/cpu: Probe the behavior of nulling out a segment at boot time
>
> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Andy Lutomirski <luto@amacapital.net>
> Cc: stable@vger.kernel.org
> ---
>
>  b/arch/x86/include/asm/cpufeatures.h |    6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff -puN arch/x86/include/asm/cpufeatures.h~fix-x86-bugs-macros arch/x86/include/asm/cpufeatures.h
> --- a/arch/x86/include/asm/cpufeatures.h~fix-x86-bugs-macros    2016-06-17 17:10:30.978602807 -0700
> +++ b/arch/x86/include/asm/cpufeatures.h        2016-06-17 17:10:30.982602989 -0700
> @@ -301,10 +301,6 @@
>  #define X86_BUG_FXSAVE_LEAK    X86_BUG(6) /* FXSAVE leaks FOP/FIP/FOP */
>  #define X86_BUG_CLFLUSH_MONITOR        X86_BUG(7) /* AAI65, CLFLUSH required before MONITOR */
>  #define X86_BUG_SYSRET_SS_ATTRS        X86_BUG(8) /* SYSRET doesn't fix up SS attrs */
> -#define X86_BUG_NULL_SEG       X86_BUG(9) /* Nulling a selector preserves the base */
> -#define X86_BUG_SWAPGS_FENCE   X86_BUG(10) /* SWAPGS without input dep on GS */
> -
> -
>  #ifdef CONFIG_X86_32
>  /*
>   * 64-bit kernels don't use X86_BUG_ESPFIX.  Make the define conditional
> @@ -312,5 +308,7 @@
>   */
>  #define X86_BUG_ESPFIX         X86_BUG(9) /* "" IRET to 16-bit SS corrupts ESP/RSP high bits */
>  #endif
> +#define X86_BUG_NULL_SEG       X86_BUG(10) /* Nulling a selector preserves the base */
> +#define X86_BUG_SWAPGS_FENCE   X86_BUG(11) /* SWAPGS without input dep on GS */
>
>  #endif /* _ASM_X86_CPUFEATURES_H */
> _



-- 
Andy Lutomirski
AMA Capital Management, LLC

[tip:x86/urgent] x86/cpu: Fix duplicated X86_BUG(9) macro

[tip-bot for Dave Hansen]

Commit-ID:  8709ed4d4b0eab04561c1ec9e6ea50fd1e3897ff
Gitweb:     http://git.kernel.org/tip/8709ed4d4b0eab04561c1ec9e6ea50fd1e3897ff
Author:     Dave Hansen <dave.hansen@linux.intel.com>
AuthorDate: Fri, 17 Jun 2016 17:15:03 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Sat, 9 Jul 2016 14:06:06 +0200

x86/cpu: Fix duplicated X86_BUG(9) macro

cpufeatures.h currently defines X86_BUG(9) twice on 32-bit:

	#define X86_BUG_NULL_SEG        X86_BUG(9) /* Nulling a selector preserves the base */
	...
	#ifdef CONFIG_X86_32
	#define X86_BUG_ESPFIX          X86_BUG(9) /* "" IRET to 16-bit SS corrupts ESP/RSP high bits */
	#endif

I think what happened was that this added the X86_BUG_ESPFIX, but
in an #ifdef below most of the bugs:

	58a5aac53313 x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled

Then this came along and added X86_BUG_NULL_SEG, but collided
with the earlier one that did the bug below the main block
defining all the X86_BUG()s.

	7a5d67048745 x86/cpu: Probe the behavior of nulling out a segment at boot time

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20160618001503.CEE1B141@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/include/asm/cpufeatures.h | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 4a41348..c64b1e9 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -301,10 +301,6 @@
 #define X86_BUG_FXSAVE_LEAK	X86_BUG(6) /* FXSAVE leaks FOP/FIP/FOP */
 #define X86_BUG_CLFLUSH_MONITOR	X86_BUG(7) /* AAI65, CLFLUSH required before MONITOR */
 #define X86_BUG_SYSRET_SS_ATTRS	X86_BUG(8) /* SYSRET doesn't fix up SS attrs */
-#define X86_BUG_NULL_SEG	X86_BUG(9) /* Nulling a selector preserves the base */
-#define X86_BUG_SWAPGS_FENCE	X86_BUG(10) /* SWAPGS without input dep on GS */
-
-
 #ifdef CONFIG_X86_32
 /*
  * 64-bit kernels don't use X86_BUG_ESPFIX.  Make the define conditional
@@ -312,5 +308,7 @@
  */
 #define X86_BUG_ESPFIX		X86_BUG(9) /* "" IRET to 16-bit SS corrupts ESP/RSP high bits */
 #endif
+#define X86_BUG_NULL_SEG	X86_BUG(10) /* Nulling a selector preserves the base */
+#define X86_BUG_SWAPGS_FENCE	X86_BUG(11) /* SWAPGS without input dep on GS */
 
 #endif /* _ASM_X86_CPUFEATURES_H */